use_self - add test case of #2843

Author: tnielens

tests/ui/use_self.fixed

@@ -336,3 +336,17 @@ mod issue4305 {
         }
     }
 }
+
+mod issue2843 {
+    trait Foo {
+        type Bar;
+    }
+    
+    impl Foo for usize {
+        type Bar = u8;
+    }
+    
+    impl<T: Foo> Foo for Option<T> {
+        type Bar = Option<T::Bar>;
+    }
+}

tests/ui/use_self.rs

@@ -336,3 +336,17 @@ mod issue4305 {
         }
     }
 }
+
+mod issue2843 {
+    trait Foo {
+        type Bar;
+    }
+    
+    impl Foo for usize {
+        type Bar = u8;
+    }
+    
+    impl<T: Foo> Foo for Option<T> {
+        type Bar = Option<T::Bar>;
+    }
+}